Plunger actuated alternate make and break switch mechanism with snap acting compression spring



Feb. 10; 1970 Filed Feb. 12, 1968 M. T. DAVY PLUNGER ACTUATED ALTERNATE MAKE ANDBREAK SWITCH MECHANISM WITH 'SNAR'AC'I'ING COMPRESSION SPRING 2 Sheets-Sheet 1 INVENTOR. MICHAEL T. DAVY ism/n Attorney Feb. 10, 1970 M. T. DAVY 3,495,058

PLUNGER ACTUATED ALTERNATE MAKE AND BREAK SWITCH MECHANISM WITH SNAP ACTING COMPRESSION SPRING Filed Feb. 12', 1968 2 Sheets-Sheet 2 INVENTOR. MICHAEL T. DAVY A ttorney United States Patent O PLUNGER ACTUATEI) ALTERNATE MAKE AND BREAK SWITCH MECHANISM WITH SNAP ACT- ING COMPRESSION SPRING Michael Theodor Davy, RR. 2, Markham, Ontario, Canada Filed Feb. 12, 1968, Ser. No. 704,805 Int. Cl. H01h 3/00, 21/04, 17/08 US. Cl. 200-153 1 Claim ABSTRACT OF THE DISCLOSURE The switch is carried in a parallel walled casing connected by an end wall having an aperture to receive a plunger. The switch mechanism is formed of a pair of telescope cylinders which enclose, a biasing spring; the cylinders ends are pivoted for see-saw movement on a pair of arms which are, in turn, pivoted for restricted opposite movement in the walls of the casing. Each arm has an extension which alternately engage with a plate adjacent the end wall of the casing. The plate has protruding edges which are located in apertures in the walls of the casing; the apertures are shaped to provide a detent on one side and travel of the enclosed edge of the plate on the other side when the plate is pressed by the plunger, which travel causes movement of the adjacent extension of the arm, whilst the other opposed edges of the plate are held in the detents. The movement of the extension of the arms causes the cylinders to pivot through a plane normal to the casing walls.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to a switch structure and has particular relation to a switch structure operated by the action of a plunger.

Description of the prior art Plunger operated switches are of particular interest to switch in and out banks of reed switches though the use of the switch of this invention is not limited thereto. A difficulty in the past has been to provide a cheap and consistently operable switch structure having a plunger action, which switch structure neither makes nor breaks until the plunger is released. The consistency of operation has hitherto been achieved only at relatively great expense as compared with other types of switch structures.

It is an object of the invention to provide a plunger 7 operated switch structure which can be constructed cheaply and which is free from failure to make or break each time the plunger is released.

It is a feature of the switch structure according to the invention that all but one of the members comprising the switch may be made of metal stampings.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in relation to the accompanying drawings, in which:

FIGURE 1 is a perspective view with portions cut away of a preferred embodiment of the switch structure constructed according to the invention;

FIGURES 2, 3 and 4 are diagrammatic representations to illustrate the operation of the switch in the make or break position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to FIGURE 1 the switch includes a channel shaped casing, generally denoted by the numeral 3,495,058 Patented Feb. 10, 1970 "ice 10, having opposed walls 12 and 14 and a connecting end wall 16. The casing 10 also has a cross member 18 formed of inwardly turned portions 20 and 22 stamped out from the walls 12 and 14. The cross member 18 has a central aperture 24.

An aperture 26 is provided in the end wall 16, the aperture 26 being large enough to permit the entry of the head 28 of a plunger 30. The free ends of the opposed walls 12 and 14 are secured by screws 32 to a casing 34 containing a group of reed switches 36.

Because each of the walls 12 and 14 have identical features and the one is the mirror image of the other in the casing 10, only one wall 12 will be described. A pair of spaced apart apertures 38 and 40 are provided in the wall 12, the apertures 38 and 40 being same distance away from the end wall 16. The apertures 38 and 40 each have adjacent inwardly disposed sides 42 and outwardly disposed sides 44, the latter being longer, and a normally disposed connecting side 46 which is substantially parallel to the end wall 16 of the casing 10. Opposed to the connecting side 40 is a side 48 formed of a portion 50 extending from the side 44 and inclined thereto; the portion 50 merges into a portion 52 which is substantially parallel to the connecting side 46, the portion 52 terminating in the side 42.

A movable plate 54 is positioned in the casing 10 to cover the aperture 26 in the end wall 16. The movable plate 54 has flanged ends 56 and 58 depending in a direction away from the end wall 16. The flanged ends 56 and 58 have lateral extensions 60, 62 and 64, 66 located in the opposed apertures 38 and 40, these extensions providing support for the movable plate. The distance apart of the flanges '56 and 58 is approximately the distance apart of the centres of the apertures 38 and 40.

The walls 12 and 14 each have a further pair of spaced apart apertures 68 and 70 of similar configuration but the former is somewhat larger to provide the requisite amount of stamped out material to form the cross member 18. The feature of both apertures 68 and 70 is the provision of a respective notch 72 and 74 located in that side of each aperture 68 and 70 farthest removed from the other.

A cylinder 76 is located in the casing 10 and traverses the central aperture 24 of the cross member 18. The aperture 24 is large enough to permit pivotal and sliding movement of the cylinder 76. The base 78 of the cylinder 76 is notched as at 80. The cylinder 76 contains a spring 82 and the cylinder 76 is closed by a sliding pin '84. A notch 86 is provided in the protruding end of the pin 84.

A pair of pivotal members 88 and 90 are located in the casing 10. The member 88 difiers from the member 90 only in that it has an arm 92, which extends in the direction of the group of reed switches 36; the hooked end 94 of the arm 92 is slidably located in an open ended aperture 96 formed in a magnetic plate 98, the movement of which controls the group of reed switches 36.

The structure of only one of the pivotal members will now be described. The member 88 has a pivot plate 100, the ends of which are located in the opposed pair of notches 72 in the side of the apertures 68 in the walls 12 and 14. The plate 100 is secured as a press fit in a fold 102 in the pivotal member 88; the inner edge of the fold 102 is cut away to expose a mid portion of the plate 100 which portion is located in the notch 80 of the cylinder 76.

The pivotal plate 88 is formed of a first portion 104 extending away from the pivot plate 100 in the direction of the movable plate 54. The first portion 104 is then bent inwards with respect to the casing 10 to form a second portion 106 and then outwards to form a flange 108.

The pivot plate 100 of the other pivotal member 90 is located in the notch 86 of the protruding pin 84 and the ends of this pivot plate are located in the opposed pair of notches 74 in the side of the apertures 70 of the walls 12 and 14.

Pivotal movement of the cylinder 76 in the cross member 18 from the position where it is tilted in one direction with reference to the end wall 16 (see FIGURE 2) to the position where it is tilted in the other direction (see FIGURE 4) would cause the flange 108 of the pivotal member 88 to move inwards with respect to the casing 12 and the flange 108 of the pivotal member 90 to move outwards.

In the position shown in FIGURE 2 the flange 108 of the pivotal member 88 bears against the flange 56 of the movable plate 54; in the position shown in FIGURE 4 the flange 108 of the member 90 bears against the flange 58 of the movable plate 54, thus moving it to the right because the flange 108 of the pivotal member 88 is moved inwards away from the movable plate 54.

The pivotal movement of the members 88 and 90 is actuated by the plunger head 28 tilting the movable plate 54, see FIGURES 2 and 3. The tilting is caused by movement downwards of the lateral extensions 60 and 62 in the opposed apertures 38 whereas the lateral extensions 64 and 66 are contained by the portions 52 of the opposed apertures 40. The length of the longer side 44 of the apertures 38 is such that the downward travel of the lateral extensions 60 and 62 cause the notched base 78 of the cylinder 76 to pass through a plane parallel to the end wall 16. As a result pivoting of the members 88 and 90 takes place and also the spring 82 is compressed in the cylinder 76. On release of the pressure of the plunger 30 the biasing effect of the spring 82 causes completion of the pivotal movement of the members 88 and 90 and also of the downwardly inclined hooked arm 92 which, in turn, provides the requisite movement of the activating magnetic plate 98.

I claim:

1. A switch mechanism including a parallel wall casing, an apertured end wall connecting the parallel walls of said parallel wall casing, a pair of spaced apart planar arms traversing said casing and pivoted in said parallel walls at points equidistant from said end wall, opposed means limiting the pivoted movement of said arms about a plane substantially parallel to the end wall, a pair of cylinders, one slidable in the other, biasing means in said cylinders, said cylinders being pivoted in said casing on the inner edges of said planar arms with said cylinders urged against said biasing means and arranged so that one of said planar arms bears against one of said opposed means and the-other arm bears against the other opposed means, each of said arms having an individual extension in spaced apart relationship, one to the other, and both terminating short of said apertured end wall and means in said casing adjacent said apertured end wall movable against either of said extensions to pivot said planar arms through a plane parallel to said end wall and means reciprocating through said apertured end wall to activate said means adjacent said apertured end wall.

References Cited UNITED STATES PATENTS 1,850,661 3/1932 Crabtree. 2,125,070 7/1938 Grooms. 2,647,179 7/1953 Martin. 3,065,644 11/1962 Riddell et a1. 74100 3,212,346 10/1965 Bachman 74-100 ROBERT K. SCHAEFER, Primary Examiner 9 ROBERT A. VANDERHYE, Assistant Examiner US. Cl. X.R. 

